Why am I allergic to the sun all of a sudden?

Why am I allergic to the sun all of a sudden?
Sun Allergy (Photosensitivity) - Harvard Health
Jun 3, 2019

A sun allergy is an immune system reaction to sunlight, most often, an itchy red rash. ... Sun allergies are triggered by changes that occur in sun-exposed skin. It is not clear why the body develops this reaction.

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